PHP计数JSON数组 [英] PHP count JSON array

问题描述

我搜索了SO但找不到答案。我的PHP脚本通过http post收到一些JSON，如下所示：

I have searched SO but couldn't find an answer.My PHP script is receiving some JSON by http post that looks like this:

{
"task": [
{
  "task_id": "3",
  "task_due": "Oct 26 11:25",
  "task_completed": "FALSE",
  "task_desc": "fff",
  "task_time": "20131026_112531",
  "task_name": "fff"
},
{
  "task_id": "2",
  "task_due": "Oct 26 11:25",
  "task_completed": "FALSE",
  "task_desc": "rff",
  "task_time": "20131026_112522",
  "task_name": "xff"
},
{
  "task_id": "1",
  "task_due": "Oct 26 11:25",
  "task_completed": "FALSE",
  "task_desc": "fggg",
  "task_time": "20131026_112516",
  "task_name": "ff"
  }
 ]}

正如你所看到的，有3个项目，但当我把它变成一个PHP数组对象并计算项目时，我返回1，当它应该是3时，这是我的PHP代码：

As you can see, there are 3 items, but when I turn it into a PHP array object and count the items, I'm returned 1, when it should be 3, here is my PHP code:

$json_tasks = $_POST["json_array"];
$task_array = json_decode($json_tasks,true);
echo count($task_array);

和回显计数打印出'1'不是'3'。

And echo count prints out '1' not '3'.

推荐答案

尝试 echo count（$ task_array ['task']）;

一般来说，如果你想知道变量值 $ var 是，做一个

In general, if you wonder what the structure of the value of a variable $var is, do a

<pre><?php var_export($var, true); ?></pre>

此功能优于序列化和 print_r 是，它打印PHP代码（因此任何理解PHP的人都可以阅读（如果你用PHP编程的话）。） var_export 的缺点是，它无法处理循环结构（例如，如果 $ a-> b == $ a ），但JSON也不行。

Advantage of this function over alternatives such as serialize and print_r is, that it prints PHP code (and is thus readable by anyone who understands PHP (which is likely if you program in PHP)). Disadvantage of var_export is, that it cannot handle circular structures (e.g. if $a->b == $a), but neither can JSON.

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